. >> tom: the big mac is feeling some heat from the whopper and the chalupa. last month, sales at mcdonald's open more than a year fell nearly 2%, its first monthly drop in nine years. the company's stock fell $1.73, or 2% today, to $85.13, its lowest close in more than a year. one reason for the slower sales is tougher competition. diane eastabrook has details. >> reporter: mcdonald's is used to serving up strong profits along with its burgers and fries. but disappointing sales in october are yet another sign that all is not well with the fast food chain. in october, global sales for stores opened at least a year were down 1.8%. in the same month last year, they were up 5.5%. analysts say mcdonald's is facing much tougher competition from other fast foods chains, and is also a victim of its own past success. >> one of the things to keep in mind too is mcdonald's has had great same-store sales the last three years, and with a three year track record like that, it's inevitable there is going to be comparisons, especially when we're dealing with negative same-st